Brake



March 8, 1932. M. w. MccoN-KEY BRAKE Filed Nov. 4. 1929 NVENTUR.

A Patented Mar. s, 1932 I UNITED STATES PATENT ori-lcs MONTGOMERY W. MCCONKEY, `OIE' SUTH BEND, IIDIANYA, ASSIGNORV T0 BENDIX BRAKE COMPANY OF SQUTE BE1TD, INDIA.'NA, A CORPORATION OF IL'LIILIS'IS Bamm j Application led November@ 1929. SerialvNo. 404,576.

'lhis invention relates to brakes and is illustrated as embodied in an internally expand-- screw is turned, it shoves both of the shoes outwardly but itself remains accurately positioned.

In the drawings in which one embodiment of the invention is illustrated: Y

Figure 1 is a vertical cross sectional view;

Figure 2A is a cross section along the line 2-2 of Figure 1;

Figure .3 is across 'section' along the line 3--3 of Figure 1; and

Figure 4 is a detail showing a slight modification of the invention.

The brake mechanism is supported within the brake drum 10 by the backing plate 12.

It consists preferably of a pair of brake shoes 14 which are anchored at 18' and arev actuated by the cam or any other desired actuator. The two shoes are articulated at the other ends by co-acting with the spaced segments 24 which are adjustably spaced apart by the adjustingscrew 28. lThe segments 24 are semi-cylindrical von their outer sides and co-act with similarly shaped' sockets fin the shoes so-that lthe shoes are free to pivot about said segments. The screw member 28 is similar toa well known type of adjusting screw having right hand thread on one end and left hand thread on the other' end and having a collar 29 at the middle with holes, notches or other' means to aid in turn- 1. ing the screw for' the purpose of adjustment.

As is well known, when the screw is turnin in one direction, both of the shoes are force outwardly, the screw always being equidistant from the twov shoes.

I have provided one or more annular reit is clear that the shoes 14 are likewise held ceases 30 in this screw member'.l and ha've put 1n one or both of said recesses the arms 32 of the centering member 34. The other end of the member 34is notched as at 36, said'jl notch co-acti'ng with a fixed or adjustable pin 38 against which it is held by spring 40. Since the screw 28 always remains centered,

vas respects the shoes 14 andsince the screw is vnormallyheld centered with respect to they drum"by centering member. 34 and pin 3,8,

centered with respect -to the drum. When the screw 2 8 is turned in'making adjustments. it remainsin the centerasfd'o both ot the shoes 14.

The operation of the brake is as follows: The cam 20 spreads apart the Vbrake shoes14 j until one or both of them contact with .the

drum 10, while the other one is anchored or becomes anchored about its anchor 18'. When the shoe 14 contacts with the rotating drum 10, 1t is rotated with the drum suiciently to thrust the-other shoe against the drum, the

thrust beingv transmitted through screw 28. This, of course, involves a movement of the adjustin screw 28, whichmovesfthe centering mem r 34, thus stretching the sprin 40.'

When the brake is released,, the re ease I springs44 draw the/shoes 14 away from the drum and the spring 40 draws the centeringv tion with pin 38, thus centering screw 28 and shoes 14. The desired normal position of the shoes 14 maybe initially secured by adjusting pin 38, but no' further'adjustment ofthe centering means will be necessary, since in 'adjustment the shoes are moved equallyy with respect to the centering means and screw 2:8.v

If desired, the member 34 may be provided with lfour arms 132 instead of two which may co-act with pin 28 in two different recesses preierablyon the two sides 'of the collar 29. This will have the etect of holding member 34 and screw 28 alittle more rigidly together. 95':

This modification is shown in Figure .4.- f

While two illustrative embodiments of my invention have been described in detail,y it is not'my intention to limit the scope of the invention to those particular embodiments or 100 member 34 back into its normal centered rel'aotherwise than by the terms of the appended claims.

I claim:

l. Brake mechanism including a backing 5 plate, twobrake shoes thereon, a right and shoes, said screw being restrained from iongitudinal movement relative to said means.

3. Brake mechanism including a brake drum, a backing late, two brake shoes on the backing plate adjacent said drum, right and left hand threaded adjusting means between said shoes, and meansl anchored on the back-r ing plate through a spring co-acting with said adjusting meansI and restrained from lon itudinal movement thereon to normally hol it in such position that the shoes will be centered with respect tothe brake drum.

4. Brake mechanism including a brake drum, a backing late, two brake shoes on the lbacking plate adjacent said drum, an adjusting screw extending between said shoes, said adjusting screw always being in centered position with respect to said shoes and means vanchored through a spring to the backing plate co-acting with said adjusting screw and restrained from longitudinal movement thereon to normally hold it in such osition that the shoes will be held in the desired poi sition with respect, to said brake drum.

. therebetween, a centering member attached ,to said adjusting device, and having a V- 5. Brake mechanism including backing late, a brake drum, two shoes adjacent said rake drum,-adjusting means pivotally connected with said shoes, said means comprising a right and left hand screw co-acting with right and .left hand thread-ed segments respectively adjacent said shoes, a recess in said screw, a forked vcentering member ce-acting with said recess and also co-actingwithfa fixed pin to normally hold .such screw inthe desired position.

6.1Brake mechanism including two vshoes spaced apart bya right and left hand screw, said screw havin" two annular indentations therein, apair ofzbifurcations co-acting with each indentation, said bifurcations being attached to a centering member which cosacts 'with'l the backing plate to normally hold the screw in the desired position.

t 7. Brake mechanism including two brake shoesfl having a floating adjusting device shaped notch normally held centered on an adjustable pin. A 8. Brake mechanism including two shoes adjustably spaced apart by an adjustin member having a ,'collar, and so arranged that said shoes approach or recede from said collar equal amounts, said adjusting member having a groove and a member c'o-acting with said groove to hold the collar in the desired position.

9. Brake mechanism including two shoes adjustably spaced apart by an adjusting member having a collar, and so arranged that said shoes approach or recede from said collar equal amounts, said adjusting member having a groove adjacent said collar, and a member co-acting with said groove to hold the collalinthe desired position.

10. Brake mechanism including two. shoes spaced apartby an adjusting screw having an annular groove and a yieldable centering member having a single pair of arms, said arms fitting in said groove.

In testimony whereof, I have hereunto signed my name. v

MONTGOMERY WV. MCCONKEY. 

